I enjoy sexual freedom that enhances a relationship. Rarely does cheating do that.
A good relationship is based upon mutual trust. That trust can include sharing. But cheating is the antithesis of a strong relationship. Cheating defeats most of the reasons one has a relationship. If you can't trust your partner how can you ever develop a deep love.
Consensual non-monogamy can be fun. Cheating, in my world, is a relationship deal killer.
This is an excellent point. Those that believe that cheating can enhance a relationship are generally living in a fantasy more end up throwing their hands up in the air wondering what happened. I would have a hard time with the moral and ethical character of the cheater. And on top of that it's already obviously don't care so how are you to assume that they would be practicing safe sex. Clearly she's not using a condom.
Seriously, I think one can get worked up a bit too much on cheating. When my wife told me she had cheated I did not get upset at all. Think about it: Imagine you were in a monogamous relationship for years but then this attractive woman comes along and tries to seduce you. Would you let that opportunity slip away because of your moral convictions? Couldn't you at least relate to someone who does not resist temptation? I know myself and I know I would have done the same thing that my wife did.
Cheating is not something that needs to destroy a relationship. Sex is not something magical that changes everything, it is just a physical activity. And as the OP and I have discovered, cheating can lead to something wonderful. It can be the conversation starter. The start of a conversation that should have happened a long time ago, but did not because partners were too afraid to talk. Not everybody is perfect, we should simply accept that. I am happy that my wife cheated on me.